The production of Upsilon(2S) and Upsilon(3S) mesons in lead-lead (Pb-Pb) and proton-proton (pp) collisions is studied in their dimuon decay channel using the CMS detector at the LHC. The Upsilon(3S) meson is observed for the first time in Pb-Pb collisions, with a significance above 5 standard deviations. The ratios of yields measured in Pb-Pb and pp collisions are reported for both the Upsilon(2S) and Upsilon(3S) mesons, as functions of transverse momentum and Pb-Pb collision centrality. These ratios, when appropriately scaled, are significantly less than unity, indicating a suppression of Upsilon yields in Pb-Pb collisions. This suppression increases from peripheral to central Pb-Pb collisions. Furthermore, the suppression is stronger for Upsilon(3S) mesons compared to Upsilon(2S) mesons, extending the pattern of sequential suppression of quarkonium states in nuclear collisions previously seen for the J/psi, psi(2S), Upsilon(1S), and Upsilon(2S) mesons.

Tumasyan, A., Adam, W., Andrejkovic, J. w., Bergauer, T., Chatterjee, S., Damanakis, K., et al. (2024). Observation of the ϒ(3S) Meson and Suppression of ϒ States in Pb-Pb Collisions at sNN=5.02  TeV. PHYSICAL REVIEW LETTERS, 133(2) [10.1103/physrevlett.133.022302].

Observation of the ϒ(3S) Meson and Suppression of ϒ States in Pb-Pb Collisions at sNN=5.02  TeV

Ciocci, M. A.;Messineo, A.;
2024-01-01

Abstract

The production of Upsilon(2S) and Upsilon(3S) mesons in lead-lead (Pb-Pb) and proton-proton (pp) collisions is studied in their dimuon decay channel using the CMS detector at the LHC. The Upsilon(3S) meson is observed for the first time in Pb-Pb collisions, with a significance above 5 standard deviations. The ratios of yields measured in Pb-Pb and pp collisions are reported for both the Upsilon(2S) and Upsilon(3S) mesons, as functions of transverse momentum and Pb-Pb collision centrality. These ratios, when appropriately scaled, are significantly less than unity, indicating a suppression of Upsilon yields in Pb-Pb collisions. This suppression increases from peripheral to central Pb-Pb collisions. Furthermore, the suppression is stronger for Upsilon(3S) mesons compared to Upsilon(2S) mesons, extending the pattern of sequential suppression of quarkonium states in nuclear collisions previously seen for the J/psi, psi(2S), Upsilon(1S), and Upsilon(2S) mesons.
2024
Tumasyan, A., Adam, W., Andrejkovic, J. w., Bergauer, T., Chatterjee, S., Damanakis, K., et al. (2024). Observation of the ϒ(3S) Meson and Suppression of ϒ States in Pb-Pb Collisions at sNN=5.02  TeV. PHYSICAL REVIEW LETTERS, 133(2) [10.1103/physrevlett.133.022302].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/1326983